System of motor control.



PATENTED APR. 3, 1906.

APPLICATION FILED JUNE 13, 1905.

INVENTOR ATTORNEY UNITED STATES PATENT OFFICE.

AX i MAGNUSON, OF NEW YORK, N. Y.,' ASSIGNOR, BY MESNE ASSIGN- .MEN TS, TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SYSTEM OF MOTOR CONTROL.

Specification of Letters Patent.

Patented April 3, 1906.

Application med June 13,1905. sesame. 264,982. 4

To all whom it may concern.-

Be it known that I, AXEL MAeNUsoN, a citizen of the United States, and a resident of New York city, in the county of New York and State of New York, have invented certain new and useful Improvements in Systems of Motor Control, of which the following is a specification.

My invention relates to a system of motor control; and it consists of a novel arrangement of various apparatus and circuits whereby an electric motor may be started, stopped,

and otherwise controlled at will.

Although my system is applicable to other types of electric motors, it may be used to great advantage in conjunction with such motors as are operated by alternating currents.

I have made application for Letters Patent, Serial No. 241,592, filed January 18, 1905, for a system of motor control which embodies the broad idea of the present invention, and the present invention is of certain improvements and developments of the invention disclosed in said prior application.

The drawing shows diagrammatically the various apparatus and circuits which I use in carrying out my.invention.

designates a motor which is to be controlled. In the drawing it is shown as an alternating-current motor.

is a directcurrent enerator, which is driven by the motor. t may be directly connected to the motor by having its shaft 21. connected to the motor-shaft 11 by a coupling 22, as shown in the drawing, or it may be connected to run with the motor in any other suitable manner.

designates a transformer, the primary of which maybe connected to a suitable source of electrical supply. Its secondary is connected by conductors 31,32, and 33 to stationary contacts 31 32 and 33*, which are a part of a magnetically-actuated circuitcloser 40, and by other conductors to other parts of the apparatus.

designates a manually-operated circuitcloser or switch, which may be situated in any convenient place and by means of which the movements of the motor may be controlled. This switch 50 comprises a movable contact-arm 51, which is pivoted at 52 and is divided into two parts, which are insulated from each other. The lower part is adapted to be moved onto two segmental contact-plates 53 and 54 and to bridge them,

and thereby electrically connect them. The plate 53 is connected to the main 32 by a conductor 53 The plate 54 is connected to the main 31 through the winding of an electromagnet 42 by a conductor 54. When the contact-arm 51 is moved onto these two plates, a circuit will be closed through the magnet 42, and the latter will be energized by a single-phase current, because connected between two of the mains. This magnet 42 is a part of the magnetically-actuated circuitcloser 40, which I will now describe more fully. It comprises an arm 41, which is pivoted at 43 and which is normally held back against a stop 44, as shown in the drawing, by a spring 45, the tension of which may be adjusted by means of a threaded screw 46. The upper end of the pivoted arm carries three insulated contacts 41, 42 and 43, which are connected by suitable conductors to the stator of the motor 10.

47 designates a direct-current electromagnet, which is arranged to cooperate with the magnet 42 in a manner which will be described later. Now when the magnet-42 is energized it will attract the arm 41 and cause its contacts 41*, 42 and 43 to be moved against the stationary contacts 31, 32 and 33", respectively, and consequently will cause the motor 10 to be connected to the mains 31, 32, and 33. The motor will therefore begin to rotate slowly. The gen- 1 erator 20, which is connected to run with the motor, will now be driven by the motor and will tend to generate a direct current which will be proportional in strength to the speed of the motor. In the drawing the directcurrent circuits are shown by light lines composed of dots and dashes. One of the leads 23 from the generator is connected to a segmental contact-plate 55 ,in the switch 50. The other lead 24 extends through a conductor 24, through the winding of magnet 47, and thence through conductor 24 to contact-plate 56 in the switch. The conductor 24 also extends to the winding of a ma net 91 and back to the lead 24 through a con uctor 24 It will be noted that when the lower part of the pivoted contact-arm 51 is moved onto and will therefore hold its contacts firmly together and prevent the chattering so comgor in alternating-current apparatus of this It will be seen that an opposition element is interposed in the rotor-circuit of the motor in the form of a star-connected resistance 70. This opposition element may be resistance or inductance or any other desired arrangement which may be used to prevent too great a flow of current. When the motor is started,

all of this resistance is preferably inserted in the rotor-circuit. The motor will not then get full power at once, but will be to ro-. tate slowly. The resistance shoul then be cut out of the circuit gradually in order to give the motor the proper acceleration. I will now describe my improved method of accomplishing this result.

A magnetic clutch- 80 is arranged to have one of its elements 81 driven by the motor. This maybe accomplished in a number of ways -as, for exam le', by connecting it directl to the motor-s aft 11 by a coupling 12, as -s own. The other element 82 of the clutch is attached to a shaft 84, which carrise a gear 85, which is also secured to the The clutch is provided with a wind-.

shaft. ing 83, which is arranged to be energized by the current from the generator .20 either directly or through the resistance 58. If the operator turnsthe contact-arm around to its extreme position, which is limited by a stop 51 all of-the resistance 58 will be out out thereby'and the clutch winding 83 will be connected directly across the generator 20 by the following conductors: conductor 23 to contact-plate-55, contact-arm 51 to lower contact 57', conductor- 57 to the clutchwinding 83, through the latter, and thence by conductor 24 to contacts 92 and 93,

which are closed, thence through conductors 24 24 and 24 to the other terminal of the generator. The clutch will thus be energized by the direct current and will cause its second element 82 and the gear 85 to rotate. There may be considerable slip between the two parts of the clutch 80, especially when the direct current is weak. This is a desirable feature, as the art of the o eration which I am about to escribe shoul not be made too rapidly, but shouldbe proportional to the acceleration of the motor, which of course will vary with different loads. The

gear 85 meshesjwith a rack 95, which is norenerator 2O be adjusted by nuts 96. T e upper d of the rack carries a contact-arm 97, wh ch is connected to the resistance and is adapted to be moved up over a series of stationary contacts 98 98 by the gear 85. These contacts 98 98 are also connected to the resist ance 70. As the arm 97 gradually moves up over the contacts 98 98 1t short-circuits the resistance 70 in a number of steps, and thereby allows the motor to rotate more rapidly. The action ofthe clutch, and therefore the movement of the contact-arm, depends upon the strength of the generated direct current, and as the stren th of this generated current depends upon t e speed of the controlled motor it is evident that the acceleration of the motor will he controlled automatically by this arrangement in the desired waythat is, its acceleration will be rapid when it is driving lightloads and slower with heavier loads. w1ll now show the purpose and operation of the holding device 90, which is above the stationary contacts 98 98. The magnet 90 mally held down by a sprin 94, whicqmay is energized by current from the generator 20,

- rod 90 and raises'a pivoted arm 90. This raises contact 93 from contact 92 and breaks the circuit through the clutch-winding 83, which will denergize the clutch. The parts will then remain in the position just de scribed until switch 50 is moved backto stop the mptor, when the circuit to magnet 91 will be broken and the parts be returned to the position shown in the drawing.

The resistance 58 is provided in the manually-operated switch for the purpose of allowing the operator to throwmore or less of this resistance into the circuit with the clutchwinding 83, and thus give the operator complete control of the clutch. He may thereby retard its action, but cannot increasedts rapidity of motion. The last contact 57' is not connected to the resistance 58, so that, if desired, the operator may cause the other parts of the apparatus to be actuated without energizingt e clutch and operating the parts it controls.

The member 82 of the clutch ma be arranged to slide laterally upon its sha t, and I have shown at 82 a lubricating means for the clutch, which may be sticks of graphite. The current may be led to the winding 83 by means of slip-rings in the usual manner.

The drawing shows no means for reversing the motor; but this may be readily added if the motor is to be used to drive an elevator, a rallroad-car, or other apparatus 1n whlch reversal-1s requlred. Means for reverslng were shown, in my prior application cited. The

drawing shows the clutch as arranged to control a resistance. It may of course be arranged to actuate any other desired form of motorcontrolling device.

i the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor.

3. A motor, a controlling device therefor, a

generator connected to run With the motor arranged to generate a current proportional in strength to the speed of the motor, an electromagnetic clutch energized by said generated current and arranged to cause the controlling device to be actuated by the movement of the motor.

4. A motor, a controlling device therefor, a

generator connected to run with the motor arranged to generate a current proportional in strength to the speed of the motor, an electromagnetic clutch energized by said generaated current and arranged to cause the controlling device to be actuated by the movement of the motor and in proportion to the strength of the generated current.

5. A motor, a controlling device therefor, a generator driven by the motor arranged to generate a variable voltage in proportion to the speed of the motor, a rotating member, means for driving said rotating member, a second rotating member connected to the controlling device, and electromagnetic means actuated by the variable voltage for imparting motion from said first rotating member to said second rotating member.

6. A motor, a controlling device therefor, a generator driven by the motor arranged to generate a variable voltage in proportion to the speed of the motor, a rotating member, means for driving said rotating member, a second rotating member connected to the controlling device, and electromagnetic means actuated by the variable voltage for imparting motion from said first rotating member to said second rotating member in proportion to the variable voltage.

7. A motor, a controlling device therefor, a generator connected to run With the motor, an electromagnetic clutch dependent upon the action of the generatorarranged to cause the controlling device to be actuated by the movement of the motor, and means for retarding the effect of the clutch on the controlling device.

8. A motor, a controlling device therefor, a generator connected to run With the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, and adjustable, means for retarding the effect of the clutch on the controlling device.

9. A motor, a controlling device therefor, a generator connected to run with the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor to automatically control the acceleration of the motor in starting, and means for holding the controlling device While the motor is running.

10. A motor, a controlling device therefor, a generator connected to run With the motor, means dependent upon the action of the generator for actuating the controlling device, and means for cutting out said first means after the controlling device has been actuated.

11. A motor, a controlling device t? erefor, a generator connected to run With the motor, means dependent upon the action of the generator for actuating the controlling device, means for cutting out said first means after the controlling device has been actuated, and a magnetic holding device arranged to hold the controlling device While the motor is run ning.

12. A motor, a controlling device therefor, a generator connected to run with the motor, means dependent upon the action of the generator for actuating the controlling device, means for cutting out said first means after the controlling device has been actuated, and a magnetic holding device deriving current from the generator arranged to hold the controlling device While the motor is running.

13. A motor, a controlling device therefor, a generator connected to run with the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, and means for cutting out the clutch after the controlling device has been actuated.

14. A motor, acontrolling device therefor, a generator connected to run with the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor to automatically control the acceleration of the motor in starting, means for cutting out the clutch after the controlling device has been actuated, and

means for holding the controlling device While the motor is running.

15. A motor, a controlling device therefor,

a generator connected to run with the motor, an electroma netic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, and a circuit-closer for the motor.

' 16. A motor, a controlling device therefor, a generator connected to run with the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, and a circuit-closer for the motor actuated by alternating currents. .Q

17. A motor, a controlling device therefor, a generator connected to run with the motor, an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, and a circuit-closer for the motor actuated by alternating currents and held by direct currents.

18. A motor, a controlling device therefor, a generator connected to run with the motor, an electroma netic clutch dependent upon the action of ale generator arranged .to cause the controlling device to be actuated by the movement of the motor, and a circuit-closer for the motor controlled by alternating and direct currents.

19. .A motor, a controlling device therefor, a generator connected to run with the motor,

.an electromagnetic clutch dependent upon the action of the generator arranged to cause the controlling device to be actuated by the movement of the motor, a circuit-closer for the motor, and a manually-o erated switch.

20. A motor, a controlling evice therefor, a generator connected torun withthe motor, means dependent upon the action of the generator for actuating the controlling device,

and a manually-operated device for regulating saidmeans.

21. A motor, a controlling device therefor, a circuitcloser for the motor, a generator driven by the motor and arranged to generate a variable voltage in proportion to the speed of the motor, means dependent upon said voltage for actuating the controlling device, and a nianuallyoperated switch for controlling the circuit-closer and regulating the actuating means for the controller.

22. vA motor, a controlling device therefor, a circuit-closer for the motor, a generator driven by the motor and arranged to generate a variable voltage in proportionto the speed of the motor, means dependent upon said voltage for actuating the controlling device, and a manually-operated switch for controlling the circuit-closer and regulating the actuating means for the controller.

23. A motor, a controlling device therefor,

a. circuit closer for the motor, a generator driven by the motor and arranged to gener-- ate a variable voltage in proportion to the s eed of the motor, an electromagnetic clutch ependent upon the variable voltage for causing the controlling device to be actuated.

by the movement of the motor but in proportion to said voltage, and a manually op ate a variable voltage in pro ortion to the s eed of the. motor, an e ectromagnetic c utch dependent upon the variable voltage for causing the controlling device to be actuated by the movement of the motor but in ropor tion to said voltage, lubricating means or the clutch, and a manually operated switch for controlling the circuit-closer and for regulating the strength of the clutch.

25. A motor, a starting-switch therefor, a generator connected to run with the motor, an electromagnetic clutch in circuit with the enerator so arran ed that its strength will 'e proportional to the speed of the motor and generator, means for closing the circuit of the clutch, and automatic means for opening the circuit of the clutch while the motor is running.

26. A motor, a starting-switch therefor, a generator connectedto run with the motor, an electromagnetic clutch in circuit with the e proportional to t e speed of the motor and generator, automatic means for opening the circuit of the clutch While the motor is running and manually-operated means for closing, regulating and opening said circuit.

27. A fpulsating current-motor, an external source 0 alternating-current supply of practically constant value, for starting and running the motor, a generator driven by the motor and arran ed to generate a direct current proportiona in strength to the s eed of the motor, a clutch having a win in circuit with said generator, arranged to be magnetized thereby, the strength of such magnetization being proportional to that of the generated current, and automatic means for opening the clutch-circuit when the current 111 said circuit has risen to a predetermined strength.

.. .AAQ

In testimony whereof I have signed my 

